Stimulation of the primary motor cortex enhances creativity and technical fluency of piano improvisations

Musical improvisation is an ecologically valid and contextually appropriate medium to investigate the neuroscience of creativity. Previous research has identified several brain regions that are involved in musical creativity: the dorsolateral prefrontal cortex (DLPFC), the ventral medial prefrontal cortex (vMPFC), the presupplementary motor area (pre-SMA), and the ventral and dorsal premotor cortex (vPMC and dPMC, respectively). These brain regions underpin high-level processing and motor functions. The present study asked whether the primary motor cortex (M1 region) plays a role in creativity and technical fluency. The M1 region underpins the acquisition and consolidation of novel motor skills and hand movement. Here, we used transcranial direct current stimulation (tDCS) to investigate the overarching research question. tDCS is a non-invasive mode of brain stimulation that is delivered via two saline-soaked electrodes diametric in charge: the anodal electrode stimulates neural activation; the cathodal electrodes inhibits neural activation. A bi-hemispheric, online tDCS montage was used in this study. Eight proficient pianists were recruited and separated into two tDCS groups: Anodal-Left M1/Cathodal-Right M1 (n = 4) and Cathodal-Left M1/Anodal-Right M1 (n = 4). tDCS was administered whilst participants performed musical improvisations. The level of creativity and technical fluency was judged independently by an expert musician adjudicator. We hypothesised that the Anodal-Left M1/Cathodal-Right M1 (excitatory) tDCS group will demonstrate an enhancement of creativity and technical fluency compared to the Cathodal-Left M1/Anodal-Right M1 (inhibitory) tDCS group. The preliminary results show that during musical improvisation, creativity (p = .07) and technical fluency (p = .05) increased when excitatory tDCS was applied to the left M1 region of proficient pianists. Furthermore, there was no apparent decrease in creativity and technical fluency for the inhibitory tDCS group. In light of these preliminary findings, we conclude that there is some evidence that the M1 region does contribute to musical creativity. Future work with a larger sample size will shed further light on this contribution.